From patchwork Mon Feb 17 18:45:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 11387399 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B3312138D for ; Mon, 17 Feb 2020 18:48:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 930C8208C4 for ; Mon, 17 Feb 2020 18:48:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Y7W3hykN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729803AbgBQSqT (ORCPT ); Mon, 17 Feb 2020 13:46:19 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:48054 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729784AbgBQSqT (ORCPT ); Mon, 17 Feb 2020 13:46:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=eXmGOwIH2jpYulUEG8Zc1CpZzmFCoe4ryYpWkEu7ztU=; b=Y7W3hykN9PWiGQMVy6Nf1Iq07d TX9lYS+aB4W/H6JX5GOUvRAO+zA72+02fKLSnf50aPbdXg8LzxxdxXjkmFWwCHMvxpZOT3tlzmJuB 172pIKk4xlwuVUmRYtUHACAYK9Bh+xwcDRCeSLG64CvWp3090uIfidiMp3wyXCl9kdp2OOjGwpl92 uyD8R1AKIdVtiFyhqmZIr5XtIGnC2sfSkEXAnFghbfjJWrSA9bi7mHKAo4LkpiOr8bKL2ngIFmsGv ljsfAJfGg8WbI3W14skTLYLZnQ9OWS8X/CkNZU7EnFJFlKh9jiTnJq0w21BYfWSNhEMKAUWUG1VfI uLiQX3mw==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j3lPL-00058n-CQ; Mon, 17 Feb 2020 18:46:15 +0000 From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, ocfs2-devel@oss.oracle.com, linux-xfs@vger.kernel.org Subject: [PATCH v6 03/19] mm: Use readahead_control to pass arguments Date: Mon, 17 Feb 2020 10:45:44 -0800 Message-Id: <20200217184613.19668-4-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200217184613.19668-1-willy@infradead.org> References: <20200217184613.19668-1-willy@infradead.org> MIME-Version: 1.0 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: "Matthew Wilcox (Oracle)" In this patch, only between __do_page_cache_readahead() and read_pages(), but it will be extended in upcoming patches. Also add the readahead_count() accessor. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 17 +++++++++++++++++ mm/readahead.c | 36 +++++++++++++++++++++--------------- 2 files changed, 38 insertions(+), 15 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index ccb14b6a16b5..982ecda2d4a2 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -630,6 +630,23 @@ static inline int add_to_page_cache(struct page *page, return error; } +/* + * Readahead is of a block of consecutive pages. + */ +struct readahead_control { + struct file *file; + struct address_space *mapping; +/* private: use the readahead_* accessors instead */ + pgoff_t _start; + unsigned int _nr_pages; +}; + +/* The number of pages in this readahead block */ +static inline unsigned int readahead_count(struct readahead_control *rac) +{ + return rac->_nr_pages; +} + static inline unsigned long dir_pages(struct inode *inode) { return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >> diff --git a/mm/readahead.c b/mm/readahead.c index 12d13b7792da..15329309231f 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -113,26 +113,29 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages, EXPORT_SYMBOL(read_cache_pages); -static void read_pages(struct address_space *mapping, struct file *filp, - struct list_head *pages, unsigned int nr_pages, gfp_t gfp) +static void read_pages(struct readahead_control *rac, struct list_head *pages, + gfp_t gfp) { + const struct address_space_operations *aops = rac->mapping->a_ops; struct blk_plug plug; unsigned page_idx; blk_start_plug(&plug); - if (mapping->a_ops->readpages) { - mapping->a_ops->readpages(filp, mapping, pages, nr_pages); + if (aops->readpages) { + aops->readpages(rac->file, rac->mapping, pages, + readahead_count(rac)); /* Clean up the remaining pages */ put_pages_list(pages); goto out; } - for (page_idx = 0; page_idx < nr_pages; page_idx++) { + for (page_idx = 0; page_idx < readahead_count(rac); page_idx++) { struct page *page = lru_to_page(pages); list_del(&page->lru); - if (!add_to_page_cache_lru(page, mapping, page->index, gfp)) - mapping->a_ops->readpage(filp, page); + if (!add_to_page_cache_lru(page, rac->mapping, page->index, + gfp)) + aops->readpage(rac->file, page); put_page(page); } @@ -155,9 +158,13 @@ void __do_page_cache_readahead(struct address_space *mapping, unsigned long end_index; /* The last page we want to read */ LIST_HEAD(page_pool); int page_idx; - unsigned int nr_pages = 0; loff_t isize = i_size_read(inode); gfp_t gfp_mask = readahead_gfp_mask(mapping); + struct readahead_control rac = { + .mapping = mapping, + .file = filp, + ._nr_pages = 0, + }; if (isize == 0) return; @@ -180,10 +187,9 @@ void __do_page_cache_readahead(struct address_space *mapping, * contiguous pages before continuing with the next * batch. */ - if (nr_pages) - read_pages(mapping, filp, &page_pool, nr_pages, - gfp_mask); - nr_pages = 0; + if (readahead_count(&rac)) + read_pages(&rac, &page_pool, gfp_mask); + rac._nr_pages = 0; continue; } @@ -194,7 +200,7 @@ void __do_page_cache_readahead(struct address_space *mapping, list_add(&page->lru, &page_pool); if (page_idx == nr_to_read - lookahead_size) SetPageReadahead(page); - nr_pages++; + rac._nr_pages++; } /* @@ -202,8 +208,8 @@ void __do_page_cache_readahead(struct address_space *mapping, * uptodate then the caller will launch readpage again, and * will then handle the error. */ - if (nr_pages) - read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask); + if (readahead_count(&rac)) + read_pages(&rac, &page_pool, gfp_mask); BUG_ON(!list_empty(&page_pool)); }